THALAMIFLOR^ 95 



and Scurvy grasses. In Erophila the petals are two- 

 cleft, and the pods are oblong, flat, or swollen. 



In the Gold of Pleasure tribe the seeds are in two 

 series, the radicle incumbent, and the Gold of 

 Pleasure and Awlwort are included here. The latter 

 is the type selected, and is a small aquatic, with 

 awl-like leaves, forming a rosette. 



In the narrowly septate group the pods are short, 

 and open from top to bottom, being flattened at 

 right angles to the narrow septum. In Wart Cress 

 the pod, how^ever, does not open. This group 

 includes two tribes, the Pepperwort tribe, in which 

 the cotyledons are straight, bent inwards or folded 

 lengthwise, with the radicle incumbent. The flowers 

 of all these plants are white. In this tribe is placed 

 Shepherd's Purse, described in the Introductory 

 Volume, as a type with pods that open, with many 

 seeds, the Wart Cresses and Pepper Cresses. 



The other tribe, or Pennycress tribe, has straight 

 seed-leaves, an accumbent radicle, pods on horizontal 

 ultimate flower-stalks, and w^hite flowers. Here are 

 included the Pennycress, in which the pods are 

 notched, the petals are equal, and the anther-stalks 

 have no scales. This type is the one selected to 

 illustrate this tribe. The Candytuft, Teesdale's 

 Cress, and Hutchinsia are other members of the same 

 tribe. 



In the group Nucumentaceae, in which the pods are 

 indehiscent or have very short valves which cover 

 a few only of the seeds, is included the Woad tribe, 



